Step 1: Nitrocellulose

This prank requires flash cotton, which is a common material used in magic tricks. It is a low density form of a widely used chemical called nitrocellulose.

Nitrocellulose is a plastic like substance, used as a wood varnish, fingernail polish, guitar picks, ping pong balls, and in the manufacture of many other useful products. In most instances nitrocellulose burns quite slowly in open air, but when in the low density form of flash cotton, it burns quickly and cleanly enough that the heat rapidly disperses into the air without burning the surface it is ignited on. This means that if done properly, small amounts of it can be lit on top of an open hand without causing a burn. This is not a recommended activity to try, as burns are of course a possibility.

In the above video I ignite far more flash cotton in my hands than what would be considered safe. I have years of experience working with nitrocellulose, and know exactly what the necessary precautions are for working with such large amounts. Under no circumstances should my actions be replicated in that respect.

Step 2: Trapping the Ash Tray

The process used to rig an ash tray with flash cotton is extremely simple. Just hide the cotton under the ash. A thick layer of ash on top of the cotton can provide a delay from when a cigarette is placed in the tray and the cotton ignites.

This prank is sure to get a big reaction, so I highly suggest that it not be used on someone who's reaction may not be a positive one. Use common sense, and don't prank in public places.

Seems like there's a lot of internet boo-hooing going on about this. Whatever who cares. I'd just like to say nice instructable. It was clear, concise, and provided adequate warning to those not responsible enough play with fire.

While I do not disagree that there are many circumstances where this, or any other prank involving fire are a bad idea, this is by no means an incendiary device according to the law. Not by any definition I have ever seen - and believe me, I've looked. An incendiary device according to every legal definition must be something that is intended to cause physical harm or damage to property. A prank does not have intent to cause harm.

For the sake of argument, lets say some psychopath really did want to use this to cause harm. Notice on the second page of this Instructable that in the last image showing the explosion you can clearly see the cigarette through the cloud. Notice also that the ash is still attached to the end of said cigarette.

The explosion is so weak that it cannot even knock the ash off the end of a cigarette, let alone cause physical harm. Even if it was intended.

Incendiary (Chemistry) (of a substance) capable of catching fire, causing fires, or burning readily. By putting nitrocellulose in a place where you know that it will ignite, by definition you're setting a tiny bomb. So if you're victim catches fire, or get an eyeful of cigarette ash, or hurts themselves trying to get away from a sudden blast of fire, it is the result of an incendiary device - there was a flame, there was an explosion.

Recently there was this: http://www.wishtv.com/dpp/news/local/north_central/woman-burnt-up-after-prank-goes-wrong

You yourself disclaim a portion of your instructable by saying "do not attempt this at home." And you had eye protection.

Oooo! Let us play the word war!Skipernicus, you specifically used the term "incendiary device" in your last post. USlegal.com defines that as the following:

An incendiary device is any firebomb, and any device designed or specially adapted to cause physical harm to persons or property by means of fire, and consisting of an incendiary substance or agency and a means to ignite it.

Examples of incendiary devices include:

1. Accelerant

2. Arson

3. Flamethrower

4. Fuel-air explosive

5. Greek fire

While flash cotton can be used as a component in some types of incendiary devices, when used in the terms of this prank, which is what it is, it is not that.

ANY prank can turn bad. A prank can always result in something you did not expect. If a person fully reads this instructable and takes certain common sense approaches to enacting it all should be well.

But like a great many things on this site, if they are used incorrectly or even just used in the wrong environment or at the wrong time dire consequences can result. But the same can be said for almost anything in life.

Thank you for your comments of additional warnings to people reading this, they are noted and will possibly warn others away that are unsure of themselves.

I will still do a prank similar to this one to a friend. He will find it amusing and I am confident in the safety of the act. But we shall see. If it goes horribly wrong I will tell you and you can sadly say I told you so.

I remember a friend who did this with a genuine "pre-explosive" made from household ingredients that didn't involve suspicious quantities of nitrogen-based fertilizer (and no, I won't disclose the compound for safety reasons). This means that it did not need access to oxygen in order to ignite. He did make a small bomb out of it but it was far more entertaining using it for this exact prank!

It's rare to find a real ash tray as full as the one used in the video--it's usually more butt than ash. There was no need for physical contact either, just the residual heat from 'ashing' was enough to set it off.

It didn't flare like the flash cotton but it was still definitely an outdoor prank because it would blow the ashtray clean (whoof!) and sometimes even took the "cherry" off the end of the offending cigarette. In an "open" environment this stuff was completely safe. I was left without about 1/2 a 35mm film canister of material which lasted for well over six months, using barely a pinch at a time.

It's really nice to see someone else has a similarly wicked but safe sense of humor!

hmmm, I have the feeling that if flash cotton were more widely available, this would be the favorite tactic of anti-smoking fanatics to get smokers to give up the habit. At every oppty, they'd lace ashtrays with this stuff to instil such an anxiety about lighting up that smokers would develop such anxiety about smoking they'd quit. LOL (I don't smoke, but some people are very fanatical about those who do smoke)

YouTube appears to have age-restricted your video. Could you please appeal the restriction (see http://support.google.com/youtube/bin/answer.py?hl=en&answer=1153367) so I (and many others) can watch it?

Per your opening headline: Make an Exploding Ash Tray - April Fool's Prank With the statement "This is not a recommended activity to try, as burns are of course a possibility." If burns are a possibility, then the following pertains.

WA. State RCW 70.74.010 definitions

(3) The term "explosive" or "explosives" whenever used in this chapter, shall be held to mean and include any chemical compound or mechanical mixture that is commonly used or intended for the purpose of producing an explosion, that contains any oxidizing and combustible units, or other ingredients, in such proportions, quantities or packing, that an ignition by fire, by friction, by concussion, by percussion, or by detonation of any part of the compound or mixture may cause such a sudden generation of highly heated gases that the resultant gaseous pressures are capable of producing destructive effects on contiguous objects or of destroying life or limb. In addition, the term "explosives" shall include all material which is classified as division 1.1, 1.2, 1.3, 1.4, 1.5, or 1.6 explosives by the United States department of transportation. For the purposes of this chapter small arms ammunition, small arms ammunition primers, smokeless powder not exceeding fifty pounds, and black powder not exceeding five pounds shall not be defined as explosives, unless possessed or used for a purpose inconsistent with small arms use or other lawful purpose.

(b) DIVISION 1.3 EXPLOSIVES: Possess a minor blast hazard, a minor projection hazard, or a flammable hazard and include propellant explosives, including smokeless powder exceeding fifty pounds. (7) The term "improvised device" means a device which is fabricated with explosives or destructive, lethal, noxious, pyrotechnic, or incendiary chemicals and which is designed, or has the capacity, to disfigure, destroy, distract, or harass.(22) The term "oxidizer" shall be held to mean a substance that yields oxygen readily to stimulate the combustion of organic matter or other fuel.

RCW 70.74.310Gas bombs, explosives, stink bombs, etc.

Any person other than a lawfully constituted peace officer of this state who shall deposit, leave, place, spray, scatter, spread or throw in any building, or any place, or who shall counsel, aid, assist, encourage, incite or direct any other person or persons to deposit, leave, place, spray, scatter, spread or throw, in any building or place, or who shall have in his possession for the purpose of, and with the intent of depositing, leaving, placing, spraying, scattering, spreading or throwing, in any building or place, or of counseling, aiding, assisting, encouraging, inciting or directing any other person or persons to deposit, leave, place, spray, scatter, spread or throw, any stink bomb, stink paint, tear bomb, tear shell, explosive or flame-producing device, or any other device, material, chemical or substance, which, when exploded or opened, or without such exploding or opening, by reason of its offensive and pungent odor, does or will annoy, injure, endanger or inconvenience any person or persons, shall be guilty of a gross misdemeanor: PROVIDED, That this section shall not apply to persons in the military service, actually engaged in the performance of military duties, pursuant to orders from competent authority nor to any property owner or person acting under his authority in providing protection against the commission of a felony.

How will you defend your actions if someone uses this instructable to excess and ends up getting hurt, hurting another person or damaging an auto, building, or other property?

Hmm. People who smoke are already putting themselves and everyone around them at risk. Where's their concern for others? Or even themselves?

BTW, you took that "burns are a possibility" out of context. The sentence right before that said, "This means that if done properly, small amounts of it can be lit on top of an open hand without causing a burn." That was then followed by, "This is not a recommended activity to try, as burns are of course a possibility." Meaning that burns are a possibility if you light the stuff IN YOUR HAND.

I'd have to agree with you to a point, some people will do this "prank" to unsuspecting victims. Anything that can turn a predictable slow burn to an instant fire ball is dangerous. Example: An ashtray in a bar, people smoking and drinking brandy. What would it take for one person to be startled by the sudden flame, knocking over the brandy? As we all know brandy/ rum etc will readily burn with an extremely hot blue flame which is difficult to see in a well lit area. Sorry Mr author, never mind the law.. You can't protect people from their own stupidity.

Ever actually tried burning vodka or brandy? They don't burn at room temperature very easily at all, even with a sustained open flame (which neither a cigarette or nitrocellulose generate.)Liquor needs to be around 100+ proof to burn at room temp.

First of all, you are quoting state law, not federal. This only applies to those residing in WA.

Secondly, you have provided a wall of text, almost entirely irrelevant to this situation even in the state in which it applies. The entire first half does nothing but define explosives, which means nothing regarding what explosives are legal and under what circumstances. Consumer fireworks are 1.4 explosives, dynamite is 1.1. Both are explosives, one is legal for consumer use, the other is not. Simply proving that flash cotton is an explosive does not make it illegal.

The only thing you have proven is that causing someone a minor inconvenience using something smelly or flammable is a misdemeanor in WA. I suppose that does make this and many other pranks a crime in that corner of the country.

You have destroyed your credibility by taking my quote out of context. The quote "This is not a recommended activity to try, as burns are of course a possibility." was not made pertaining to this prank, but to igniting flash cotton on an open hand. In context, the quote is as follows:

"This means that if done properly, small amounts of it can be lit on top of an open hand without causing a burn. This is not a recommended activity to try, as burns are of course a possibility."

In response to your question of how I will defend my actions if someone else causes injury - I will not. I have done nothing but provide information meant to be entertaining to my viewers. I am no more responsible for people abusing information that can be found on the internet than the person that shows how to shingle a roof is when someone following those instructions falls off a ladder.

The burden of proof is not on me to justify my Instructable, you are the one who has taken issue with it. If you say it's not your problem, and I certainly don't have a problem with it, I guess nobody has a problem do they.

The crew on Fact or Faked did an investigation of an ashtray at a bar that supposedly had "exploded". I wonder if what actually happened was something along the lines of this instructable. I never did see the conclusion of that "investigation" though.